A simple kernel module was used to create concurrent soft and hard lockups:
http://ozlabs.org/~anton/junkcode/badguy.tar.gz Signed-off-by: Anton Blanchard <an...@samba.org> --- kernel/watchdog.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 70bf118..dd161e3 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -19,6 +19,7 @@ #include <linux/sysctl.h> #include <linux/smpboot.h> #include <linux/sched/rt.h> +#include <linux/die_lock.h> #include <asm/irq_regs.h> #include <linux/kvm_para.h> @@ -313,6 +314,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) struct pt_regs *regs = get_irq_regs(); int duration; int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace; + unsigned long flags; /* kick the hardlockup detector */ watchdog_interrupt_count(); @@ -384,6 +386,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) } } + die_spin_lock_irqsave(flags); pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", smp_processor_id(), duration, current->comm, task_pid_nr(current)); @@ -394,6 +397,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) show_regs(regs); else dump_stack(); + die_spin_unlock_irqrestore(flags); if (softlockup_all_cpu_backtrace) { /* Avoid generating two back traces for current -- 2.1.0 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
